Stable voltage/cpu freq combinations will differ for different units but it's pretty easy to find them. I use the following process:

Get Droid Overclock

Make one of your slots in Advanced/Custom the target cpu freq

Set the voltage fairly high. Mine runs stable with 58 at 1GHz. You might try that as a start or use the default at 1GHz of 62 I believe.

Make sure "Apply on boot" is not checked and hit "Apply Preset"

Set your CPU Min/Max scaling to your target frequency and disable any profiles.

Fire up SetCPU and run the Stress Test for a few minutes. If you see the spinning loop turtle or your phone freezes, your voltage is too low. Go to step #3 and increase by one. If everything keeps running, go to step #3 and decrease voltage by one.

You can try Quick Clock but every voltage it's ever suggested to me has been too low or too high. They apply ok and the phone will run but under stress testing it locks up.